SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acef8117625deb9d6b57b743b95ce356eceea8d637594d37968f8a16c95e58f4' 
  AND token = 'D1zEf325NuXpdcdIzceG7Z1Qu5GWZpmYA69eTTXFtW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}